root

Noun

root (countable and uncountable, plural roots)

2. The part of a plant, generally underground, that anchors and supports the plant body, absorbs and stores water and nutrients, and in some plants is able to perform vegetative reproduction.

   Hyponym: taproot

   This tree's roots can go as deep as twenty metres underground.

   • 1981, Frank Herbert, God Emperor of Dune‎, →ISBN, →OCLC, page 6:

     A root caught Ulot's left foot and he almost fell.

3. A root vegetable.
   • 1943 November – 1944 February (date written; published 1945 August 17), George Orwell [pseudonym; Eric Arthur Blair], Animal Farm […], London: Secker & Warburg, published May 1962, →OCLC:

     [...] two fields which should have been sown with roots in the early summer were not sown because the ploughing had not been completed early enough.

4. The part of a tooth extending into the bone holding the tooth in place.

   Root damage is a common problem of overbrushing.

5. The part of a hair under the skin that holds the hair in place.

   The root is the only part of the hair that is alive.

6. The part of a hair near the skin that has not been dyed, permed, or otherwise treated.

   He dyed his hair black last month, so the grey roots can be seen.

7. (figurative) The primary source; origin.

   Synonyms: basis, origin, source

   The love of money is the root of all evil.

   • 1689 December (indicated as 1690), [John Locke], Two Treatises of Government: […], London: […] Awnsham Churchill, […], →OCLC:
     , Book 1

     They were the roots out of which sprang two distinct people.

   • 1936, Rollo Ahmed, The Black Art, London: Long, page 160:

     Phallicism was, therefore, at the root of all religion, and was definitely the opponent of evil and darkness.

8. (aviation) The section of a wing immediately adjacent to the fuselage.
9. (engineering) The bottom of the thread of a threaded object.

   Antonym: crest

   The root diameter is the minor diameter of an external thread and the major diameter of an internal one.

10. (arithmetic) Of a number or expression, a number which, when raised to a specified power, yields the specified number or expression.

    Hyponyms: cube root, functional root, square root

    The cube root of 27 is 3.

11. (arithmetic) A square root (understood if no power is specified; in which case, "the root of" is often abbreviated to "root").

    Multiply by root 2.

    • 1899, Dante Gabriel Rossetti (transl.), The New Life (La Vita Nuova) of Dante Alighieri, Siddall edition, page 122.

      The number three is the root of the number nine; […] being multiplied merely by itself, it produceth nine, as we manifestly perceive that three times three are nine.

13. (mathematical analysis) A zero (of an equation).

    Synonym: zero

    Antonym: pole

    Holonym: kernel

14. (graph theory, computing) The single node of a tree that has no parent.
15. (linguistic morphology) The primary lexical unit of a word, which carries the most significant aspects of semantic content and cannot be reduced into smaller constituents. Inflectional stems often derive from roots.

    Coordinate term: stem

    • 1530 July 18, Iohan Palſgrave, “The Introduction”, in Leſclarciſſement de la langue francoyſe […] ‎, London: Richard Pynſon, Iohan Haukyns, →OCLC, page 32; reprinted as Lesclarcissement de la langue françoyse, Genève: Slatkine Reprints, 1972:

      In ſo moche that if any verbe be of the thyꝛde coniugation / I ſet out all his rotes and tenſes […]

    • 2006, Donald Ringe, From Proto-Indo-European to Proto-Germanic (A Linguistic History of English; 1)‎, Oxford: Oxford University Press, →ISBN, page 12:

      A considerable number of derived nominals, especially thematic nouns, also exhibited o-grade roots.

16. (linguistics) A word from which another word or words are derived.

    Synonym: etymon

17. (music) The fundamental tone of any chord; the tone from whose harmonics, or overtones, a chord is composed.^[1]
18. The lowest place, position, or part.
    • 1667, John Milton, “Book X”, in Paradise Lost. […], London: […] [Samuel Simmons], and are to be sold by Peter Parker […]; [a]nd by Robert Boulter […]; [a]nd Matthias Walker, […], →OCLC; republished as Paradise Lost in Ten Books: […], London: Basil Montagu Pickering […], 1873, →OCLC:

      deep to the roots of hell

    • 1812, Robert Southey, Omniana:

      the roots of the mountains

19. (computing) In UNIX terminology, the first user account with complete access to the operating system and its configuration, found at the root of the directory structure; the person who manages accounts on a UNIX system.

    Synonyms: superuser, root account, root user

    I have to log in as root before I do that.

20. (computing) The highest directory of a directory structure which may contain both files and subdirectories.

    Coordinate term: home directory

    I installed the files in the root directory.

21. (slang) A penis, especially the base of a penis.

Verb

root (third-person singular simple present roots, present participle rooting, simple past and past participle rooted)

1. To grow roots; to enter the earth, as roots; to take root and begin to grow.

   The cuttings are starting to root.

   • 1707, J[ohn] Mortimer, The Whole Art of Husbandry; or, The Way of Managing and Improving of Land. […], London: […] J[ohn] H[umphreys] for H[enry] Mortlock […], and J[onathan] Robinson […], →OCLC:

     In deep grounds the weeds root the deeper.

   • 2014 October 26, Jeff Howell, “Is the Japanese knotweed threat exaggerated? Our troubleshooter calls for calm about Japanese knotweed in the garden – and moss on the roof [print version: Don't panic about an overhyped invasion, 25 October 2014, p. P13]”, in The Daily Telegraph (Property)‎:

     Some old, underfired clay pantiles might be damaged by button mosses rooting in cracks and fissures. But most post-war tiles are hard enough to withstand a bit of moss growth.

2. To prepare, oversee, or otherwise cause the rooting of cuttings.

   We rooted some cuttings last summer.

3. To fix firmly; to establish.
   • 1823, Gilbert Burnet, The Life of Sir Matthew Hale, Knt., Sometime Lord Chief Justice of His Majesty's Court of King's-Bench:

     If any irregularity chanced to intervene and to cause misapprehensions, he gave them not leave to root and fasten by concealment.

   • 1981 April 18, Michael Bronski, “Good Production — Bad Play”, in Gay Community News, page 10:

     Small theater companies come and go very quickly — many times after one show — but community response to Triangle has been strong, and there is a good chance that they will make it through those early growing stages and firmly root.

   • 2020 October 15, Frank Pasquale, “‘Machines set loose to slaughter’: the dangerous rise of military AI”, in The Guardian‎:

     Massacres that take place during war often seem to be rooted in irrational emotion.

5. (computing slang, transitive) To get root or privileged access on (a computer system or mobile phone), often through bypassing some security mechanism.

   Synonym: (mobile phone) jailbreak

   We rooted his box and planted a virus on it.

   I want to root my Android phone so I can remove the preinstalled crapware.

Verb

root (third-person singular simple present roots, present participle rooting, simple past and past participle rooted)

2. (transitive, intransitive) To turn up or dig with the snout.

   A pig roots the earth for truffles.

   • c. 1515–1516, published 1568, John Skelton, Againſt venemous tongues enpoyſoned with ſclaunder and falſe detractions &c.:

     Such tunges ſhuld be torne out by the harde rootes,
     Hoyning like hogges that groynis and wrotes.

3. (by extension) To seek favour or advancement by low arts or grovelling servility; to fawn.
   • c. 1593 (date written), William Shakespeare, “The Tragedy of Richard the Third: […]”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC, [Act I, scene iii]:

     Thou elvish-marked, abortive, rooting hog!

4. (intransitive) To rummage; to search as if by digging in soil.

   Synonyms: dig out, root out, rummage

   rooting about in a junk-filled drawer

5. (intransitive) Of a baby: to turn the head and open the mouth in search of food.
   • 2016, Rachel Waddilove, The Baby Book: How to enjoy year one: revised and updated, page 179:

     When your baby is rooting, his head will turn to the side and he will open and close his mouth. If you put your finger in your baby's hand, she has a grasping reflex that makes her curl her fingers around yours and hold on.

6. (transitive) To root out; to abolish.
   • 1595 December 9 (first known performance), William Shakespeare, “The life and death of King Richard the Second”, in Mr. William Shakespeares Comedies, Histories, & Tragedies: Published According to the True Originall Copies (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC, [Act IV, scene iv]:

     I will go root away the noisome weeds.

   • 1611, The Holy Bible, […] (King James Version), London: […] Robert Barker, […], →OCLC, Deuteronomy 29:28:

     The Lord rooted them out of their land [...] and cast them into another land.

7. (equestrianism, of a horse) To tug or pull at the reins aggressively by driving the head downwards while wearing a bit.
8. (Australia, New Zealand, Ireland, vulgar, slang) To sexually penetrate.

   Synonyms: screw, bang, (US) drill, (British) shag; see also Thesaurus:copulate with

Noun

root (plural roots)

1. (Australia, New Zealand, vulgar, slang) An act of sexual intercourse.

   Synonyms: (UK, US) screw, (UK) shag; see also Thesaurus:copulation

   Fancy a root?

   • 2018, Melissa Lucashenko, Too Much Lip, University of Queensland Press, published 2023, page 113:

     Ken was in the good mood he'd been in for weeks. Nothing like a regular root to turn him into the jolly green giant.

2. (Australia, New Zealand, vulgar, slang) A sexual partner.

   Synonym: (US) screw

Verb

root (third-person singular simple present roots, present participle rooting, simple past and past participle rooted)

1. (intransitive, with "for" or "on", US) To cheer (on); to show support (for) and hope for the success of. (See root for.) [late 19th century]

   Synonyms: (Australia, New Zealand) barrack, cheer on

   I'm rooting for you, don't let me down!

   • 1908, Jack Norworth, Take Me Out to the Ball Game:

     Let me root, root, root for the home team,

See also

• 越獄／越狱 (yuèyù, “to jailbreak”)

Declension